Physicians like neurologists and urologists, physiatrists, physical therapists, chiropractors, and other medical providers have used nerve and muscle stimulation to treat a variety of ailments. These medical providers have used various methods of neurostimulation and neuromodulation such as implanted electrical and optical devices and external electrical, magnetic and ultrasonic devices for treatments such as deep brain stimulation for Parkinson's disease and electronic muscle stimulation (EMS) and transcutaneous electrical nerve stimulation (TENS) for muscle and joint rehabilitation as well as chronic pain. Urologists and obstetrician/gynecologists have used a form of TENS for pelvic floor stimulation to treat urge incontinence, urinary frequency, non-obstructive urinary retention, interstitial cystitis, chronic pelvic pain, anal incontinence and other pelvic neuromuscular disorders.
Transcutaneous stimulators, i.e., stimulators which do not physically penetrate the skin surface, are less invasive than percutaneous and implantable stimulators. However, transcutaneous stimulators often require higher current levels than percutaneous and implantable stimulators. Higher current levels can cause irritation and discomfort when used for extended periods. Also, since transcutaneous stimulators stimulate on the skin surface, their target site usually covers a large area. Thus, transcutaneous stimulators may not be highly effective for direct nerve stimulation. This is especially true for stimulation targets that are deep to the skin surface and that may be shielded by overlying hard tissue.
More typically, providers use implantable stimulators when there is a need for direct nerve stimulation or continuous stimulation. Implantable stimulators can free a patient from the need for constant and frequent manual treatment. However, implantable stimulators can cause mild discomfort, and often cause more severe implant-site pain.
Percutaneous stimulators provide direct nerve stimulation without the invasiveness of an implant. During treatment, a conducting needle is inserted to provide electrical stimulation to a target nerve. The needle is electrically connected to a controller by a series of leads, often bound together at one end as a cable that connects to the controller. When positioned properly, the needle (which includes a receiver/electrode assembly) stimulates the tibial nerve thereby modulating nerve activity in the sacral plexus. Modulation or interruption of sacral nerve activity is useful in the treatment of the pelvic heath disorders enumerated above.
However, the needle must be precisely and accurately positioned to achieve the maximum heath benefit. There are currently no devices that facilitate or guide accurate percutaneous delivery of a needle, wire, trocar or cannula to a target spatial location on or within tissue that can be utilized by both medical personnel and patients.
Therefore, what is needed is a device that uses an anatomic landmark or fiduciary point to establish a point of origin for device orientation in space. What is also needed is a device that can control the direction and depth of delivery of the needle, wire, trocar or cannula that is part of the diagnostic or therapeutic intervention.